Tunneling machine



(Nomadel.) aaneen-.sheen 1.

J. L. MITCHELL.

TUNNBLING MAQHINB.

No. 537,899. Patented Apr. 2s, 1895.

(No Model.) 3 sheets-sneen :2. Y

J. L. MITCHELL. TUNNELING MACHINE.

yNo. 537,899. PatentedApr. 2s, 1995.

(No Model.) 3 sheets-sheet s.

J. L. MITCHELL. TUNNELING MACHINE.

N0. 537,899. Patented Apr. 23, 1895.

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JONAS I.. MITCHELL, OF CHICAGO, ILLINOIS.

TUNNELING-MACHINE. I

SPECIFICATION forming part of Letters Fatent No. 537,899, dated April23, 1895.

Application tiled April 3. 1893.

T0 all whom t may concerne Be it known that I, JONAS L. MITCHELL, acitizen of the United States, residing at Chicago, in the county of Cookand State of Illinois, have invented certain new and useful Improvementsin Tunneling-Machines, of which the following is a specification,reference being had therein to the accompanying drawings.

This invention relates to improvements in tunneling machines, that is tosay, machines intended to cut an aperture in coal or rock of such naturethat the entire machine can be propelled through it.

Figure l is a longitudinal, horizontal section of a machine embodying myimprove- Fig. 4. is a vertical transverse section onV ther Fig. 5 showsan enlarged line 1J-y of Figi. section ot' the tubular support, and theadjacent parts. Fig. 6 shows in detail the antifriction bearing for thecutter head. Fig. 7 shows in section a portion of the tubular cutterhead with the internal gearing. Fig. 8 shows in detail the manner ofsecuring the tubular support to the carriage bars.

The frame work of the machine comprises two parts,`one being the mainframe orbed, and the other being the cutter support or frame. In respectto either of these parts there can be numerous modifications withoutdeparting from the essential features of the invention.

As shown in the drawings, the bed-frame contains parts A A each of whichis preferably formed of two curved metallic bars a a hinged together ata2, and at their upper ends adapted to approach and recede from eachother somewhat fora purpose to be described. These ring-likeframe-supports arepreferably arranged one at the forward end and theother at the rearend of the bed, and they are connected together bymeans of any suitable lougitudinal girts or bars, and have sheets B ofsheet metal secured thereto for the purpose pose of inclosing theoperative parts and of obtaining an extended frictional surface ofcontact with the wall of the tunnel. The upper part and the lower partof each ring section may be connected by vertical bars or uprights forsupporting portions of the operative parts of the machine, as will bedescribed.

At C C there are guides carried by the bed Serial No. 468,909. (Nomodel.)

frame which are for the purpose of guiding the cutter'carrierorsupporting it in its movements relatively to the bed.

The cutter frame or support comprises longitudinally arranged bars orcarriers D which are fitted in the above described guides at C. At theirforward ends these carrier bars carry a short tube E of large diameter,and to which they may be secured by means of plates at E. This plate maybe made integral with. the tube E or may be rigidly secured thereto.. Atthe rear ends and at intermediate points the Asliding carriers may beconnected by any suitable girts.

The cutter-head proper consists of a tube F which at its rear end fitsin the tube E, but projects forward considerably beyond it. At the frontedge it is formed or provided with sockets for receiving the cuttersf,and at the rear end it is formed with gear teeth f', and with a bearingflange f2. The cuttersfcan be adjusted so that one shall attack thematerial along one circle ot' rotation, and another on another circle,and they are so disposed that they will form an aperture of a diametergreater than that of the machine.

The cutter head F can be rotated within the stationary tube E, and theback pressure from the cutters is received upon a series ofanti-friction balls or rollers at G placed. between the bearingvflangef2 and the flange or plate E. As the tube E is supported upon thecarriers D, and the tube F is in turn .supported in the tube E, it willbe seen that the latter will be advanced with the carriers D as they areforced forward.

Power for rotating the revolving cutterhead or tube F is imparted to itsgear f by pinions H. The latter are secured to longitudinally arrangedshafts I which are mounted in bearings carried by the cutter-supportingframe. At the rear ends these shafts have beveled wheels which mesh withbeveled pinionsj on the crank shaft J, which shaft is also mounted insuitable bearings secured to the cutter carriage. The shaft is rotatedby engines whose cylinders are shown at K, and which are adapted to beactuated by steam, compressed air, water or other driving agent. Theengines are arranged horizontally and are so placed as to leave as largean opening as possible on the central longitudinal lines of thelnachine'and extending through it.

It will be seen that when the engines are in operation the rotation ofthe cutter head F will be caused through the crank shaft J, beveledwheels t and j, shafts l, pinions I-I and gearingf.

At the same time the cutters are rotating, they can be simultaneouslyadvanced relatively to the bed by means of the parts at L, L. L is acylinder, and L is a piston rod, with its piston Zat one end in the saidcylinder. At

1o the other end, the piston rod L bears against the upright or bar Msecured to the bed. Preferably there are two feeding cylinders L on eachside of the machine, and there are pipe or hose connections ot' suchsort that 1 5 water, compressed air or other suitable agent can bedelivered to the interior of the cylinders behind the pistons Z. WVhenthe feeding agent is so delivered, the cutter carriage or frame and thecutters will 'be advanced relazo tively to the bed, as the cylinders Lwill be 3o side of the machine.

forced forward away from the bars M, said cylinders at their front endsbeing connected to uprights or other suitable bars N secured to thecutter carriage.

For the purpose of drawing the cutter head and the cutters back upon thebed, I use one or more cylinders O and piston rods O with pistons at 0inthe cylinders, there being preferably two such cylinders and pistons oneach The piston O is secured to bars carried by the bed,and the cylinderO is at the rear end secured to bars attached to the carriage. When thecutter has advanced to the end of its movement, the pis` tons o are inthe rear ends of cylinders O,

and ifA water, air, steam or equivalent be let into said rear endsbehind the pistons, the cylinders will be forced backward, bringing withthem the cutter-frame and cutters. This 4o last described mechanism canalso be used for drawing the parts I have referred to as the bed-frame,forward relatively to the cutter.

By placing the hydraulic cylinders and pistous as shown in the drawings,near the /sheating, or the tunnel walls, and above and 5o the points atwhich the cutters attack the coal.

With most of the earlier machines for driving tunnels with which I amacquainted, it has been customary to use a central shaft which not onlyforms part of the mechanism for rotating the cutters, and serves as acarriage for supportingthem, but also is threaded and utilized to feedpositively the cutters forward, there beinga stationary nut engaging 6otherewith for this purpose; but I have found a positive feed isdisadvantageous and sometimes useless in many cases, where the materialvaries in density, and that in order to obtain the best results, ayielding feed must be employed, and that the power, as said,

must be distributed to points where there is the greatestresistance-namely, in line with the points of engagement of the cutterswith the material to be cut. In order to support the cutters in theirproper relations to the bed, I employ as aforesaid, a carriage whichslides on said bed, and is supplemental to and entirely independent ofthe feeding mechanism, so as far as concerns the feeding mechanismacting as a support and which is preferably utilized to support theengines and the shafting and gearing for rotating the cutters.

I am aware that it -is not new to utilize hydraulic feeding devices, anddo not wish to be understood as claiming such broadly as of myinvention; but as heretofore used, the cylinders and pistons were eitherarranged centrally longitudinally of the machine, or were all below thecentral longitudinal plane of the machine, and not placed above andbelow it, so as to properly distribute the power, as is done in mymachine; and in some of such machines the feed mechanism acted asasupport for the carriage, whereas as above said my carriage issupported independent of the feed mechanism.

At the rear end of the cutter frame, hydraulic jacks are placed, asshown at P and P', the former being a cylinder and the latter pistonrods with pistonsp adapted to force points or armsp outward with suchpower as to cause them to engage firmly with or enter the wall of thetunnel. The two pistons p can be in a single cylinder, and by applyingthe water, steam or other agent between them they can be forced outsimultaneously.

One or both of the ring-like supports of the bed arev provided with acylinder Q, piston rod Q and piston q. The cylinder Q is pivoted to thesection a', and the piston rod Q" is pivot'ed to the section a, so as toprovide sufficient flexibility of attachment. Through suitableconnections, water or the like can be admitted to the cylinder Q, and byits pressure upon the piston q a powerful expansive action will beexerted upon the two hinged sections a a under which they will engagewith the tunnel walls with great firmness.

The central part of the machine is soopen longitudinally and free fromobstructions, particularly in the lower part, that the operatives canhave free access tothe material inclosed within the circle of cut; andwithin this space I frequently mount a conveyer, as shown at S, which.may be of any suitable sort. By it, the cut material can be carriedbackward beyond the rear of the machine and either dropped upon thebottom of the tunnel or loaded into a vehicle intended to remove it.

The manner of operation of the machine above described will be readilyunderstood.

Supposing that the parts of the machine are in the relative positionsshown in Fig. l, and that the cutters are ready to enter the coal orrock, water or the other selected agent is admitted to the cylinders Qfor the purpose of binding the bed-frame firmly to the tunnel wall inthe way above described. The steam,

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compressed air or other driving material is admitted to the engines at KK, whereupon the rotating of the cutters will be effected, as has beenset forth; and at the same time the water or the like is admitted to thecylinders L L, and asa result the cutters and their supporting andactuating devices will be advanced. As soon as the cutters have formedtheir annular slot to the desired depth (which will be governed by thedistance from the cutter points to the gearing f,) the engines and themovements of the cutters are stopped. The water is cutoff from thecylinders Land admitted to the cylinders O, as a result of which thecutter frame and the cutters will be drawn back again to the relativepositions shown in Fig. l. Thereupon, the core surrounded by the newlyformed kerf is loos` ened, and after being loosened is passed backwardthrough the central part of the machine by means of the con veyer orotherwise. Then the water is again admitted to the cylinders L L whichagain advance the cutters. Thereupon the pressureis admitted to thecylinder P which forces out the jack points or arms p" into powerfulengagement with the coal, andthe cutter frame or support is firmly boundto the tunnel wall. Then the pressure is cut oft from the cylinders Q,so as to release the rings A and the main frame from engagement with thetunnel Wall, and it is admitted again to the cylinders O, the result ofwhich is to force the rings A A with their sheet iron jacket B B forwardrelatively to the cutter frame until the parts are again in the positionshown in Fig. l. Then the pressure is again admitted to the cylinders Q,and released from the cylinder P; after which the machine is ready for asecond operation.

I am aware that a machine forboring tunnels in soft chalky material hasbeen made or proposed, it having two casing shells or sheathings, one toserve as a carriage,and the other as an abutment, the carriage shell aswell as the bed shell being divided along the top.

The present machine is in many respects radicallydifferent from the oneto which I have just referred. I have indeed, two tubular shells orcasing sheaths, one connected with the carriage, and the other beingpart of the bed; but my carriage shell or casing has a Ycontinuousunbroken extension wall,

not being split or divided as in the earlierconstruction. Again, for thebed I have a strong frame consisting of hinged .curved bars connected tothe shield or casing, by means of which I am not only able to supportand move said casing, but am also able to give a firm support to thecarriage which projects back through the bed part, and is provided withfastening devices in the rear thereof. The length of the machine as awhole can be thus reduced to one half of thatof the earlier one.

It is obvious that as the curved bars are forced outward against thetunnel walls, they In my construction, thc carriage shellsupports thetubular cutter head, and is rigidly secured to the frontend of thecarriage, which consists of a rectangular frame having side bars, thelatter sliding in the guides in the said curved bars. Both the carriageshell, and the bed shell are of a diametermuch less than that of thecircle of rotation of the cutters. With such an arrangement, there is nofrictional engagement of the carriage with the tunnel walls to beovercome in feeding the cutters to their work, such as is experienced inthe earlier machine. Then too, in order to have the power uniformlydistributed on the proper lines when feeding the carriage and bed framealternately, and iu order to get as much central space as possible inthe machine, as well as to obtain the requisite amount of piston area inthe cylinders, I use two sets of hydraulic cylinders and pistons. In thesaid earlier machine, four pistons and cylinders and pistons wereuniformly disposed on the shell, each being used for the forward and therear portions of the tubular shell alternately; but I have found thatpiston rods of relatively large diameter must be employed to preventtheir bending, and that when the cylinder is of a size to get sufficientpressure on the free side of the piston, that there is not enough pistonarea on the opposite side of the piston to provide sufficient power fordrawing the bed up for a new cut. Therefore, either a cylinder of greatdiameter must be employed, or, as I have found it more practicable, asepa rate set of cylinders.

It will be seen that the cylinders in my machine are very long and ofcomparatively small diameter, the piston rods being relatively large incross section to be sufficiently strong, and also that the feedingcylinders for driving the cutters forward are placed as near as possiblein the line of the out, and that the bed advancing cylinders are placedrelatively near the carriage side bars in order to get a direct pullalong the lines of the guides.

I am also aware that tunneling machines have been proposed withcentrally supported IOC cutter heads, but I do not claim these, theybeing materially different from the centrally.

connected to the carriage in lines near the Walls of the tunnel, a rackarranged on the inside of said cutter head, and a wheel H mounted on thecarriage and engaging said rack in said cutter head for rotating saidhead, substantially as set forth.

2. In a tunneling machine, the combination with the bed adapted to befastened to the tunnel wall, of the cutters, the cutter carriageprojecting beyond the rear of the bed, and the cylinder and twooppositely acting Wall engaging pistons mounted on said carriage in rearof said bed, substantially as set forth.

3. In a tunneling machine, the combination with the bed, and thehydraulic piston and cylinder for fastening said bed to the tunnelwalls, of the cutters infront of said bed, the sliding carriage forsupporting and advancing said cutters and extending from the cutters topoints in the rear of the bed, and the hydraulic piston and cylinderhaving two well engaged spurs, both movable relatively to the carriagemounted on said carriage in rear of said bed, whereby said bed, and saidcarriage may be alternately fastened to the tunnel walls, substantiallyas and for the purposes set forth.

4. In a tunneling machine, the combination of the bed having guidesupports situated in the central longitudinal diameter of the tunnel,one on each side of the axis, the carriage projecting through the bedand traveling in the said guide supports, the tunnel cutting apparatusmounted upon the said carriage, means for rotating the cutters, meansfor moving the carriage, the external shellsurrounding the bed, andmeans for forcing said shell against the tunnel walls, substantially asset forth.

5. In a tunneling machine, the combination with the tunnel formingcutter, and the rectangular carriage frame supporting and advancing saidcutters to their work, having longitudinal side bars and cross-bars, ofthe relatively stationary bed frame consisting of two or more pairs ofhinged curved bars, means for forcing them apart at their endsintoengagement with the tunnel walls, and means for connecting saidpairs of bars together, said curved bars having guides for saidlongitudinal carriage bars, substantially as and for the purposes setforth.

6. In a tunneling machine, the combination of the cutter carriage, thebed which supports said carriage vertically and is formed in twohorizontally separable parts whereby it can be spread for fasteningagainst the tunnel walls, a cutting apparatus secured to the carriage, anon-rotary shell or casing secu red lrigidly to the carriage whichadvances away from lthe bed, and having a continuous or unbrokenexternal wall, a rotary hollow cylindrical cutter head supported in thesaid nonrotary casing, and means for fastening the carriage to thetunnel walls at points in rear of the bed, substantially as set forth.

7. In a tunneling machine, the combination of the bed having an externalcylindrical sheathing, interior bars hinged together, and supporting thesaid sheathing at points in a curved line approximating a circle, meansfor forcing said hinged bars apart, the carriage supported on the saidhinged bars of the bed, and the rotary cutting apparatus at the front ofsaid bed, substantially as set forth.

8. In a tunneling machine, the combination of the cylindrical bed havingvertically arranged frame bars and an exterior cylindrical casing shellsecured thereto, means for fastening said bed to the tunnel walls, the

cutting apparatus at the front, the carriage for said cutting apparatusextendingback through the cylindrical bed and consisting of side barsand end bars, a wheelH for rotating the cutters, the two enginecylinders mounted similarly relatively to the axis of the bed, and theshafting connecting the cylinders with the said wheel H, said cylindersand said shafting being mounted on said carriage, substantially as setforth.

9. In a tunneling machine, the combination of the bed having the curvedframe bars, means for fastening them to the tunnel walls, guides on saidcurved bars, a carriage having side bars sliding in said guides, thetubular cutter head mounted on the carriage, and means for advancing thecarriage relatively to the said bed frame, substantially as set forth.

10. In a tunneling machine, the combination of the abutment bed, thecarriage having guides sliding in supports on said bed, the tubulartunnel forming cutter' having an annular groove at its inner end, thetubular support for said cutter mounted on said carriage and. having aninwardly turned flange, said flange having an annular groove, andanti-friction balls working in said grooves, substantially as and forthe purposes set forth.

11. Inatunneling machine, the combination with the stationary bed havingguide supports, the tunnel forming cutters, and means for rotating saidcutters, of the carriage having side guides sliding in the aforesaidguide supports on the bed, and one or more pistons and cylinders,supplemental to said carriage and said guides, for feeding the carriageand JONAS L. MITCHELL.

Witnesses:

CLARENCE E. SMITH, B. F. KENT.

